• Journal of Gastric Cancer
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• v.14 no.3
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• pp.187-195
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• 2014

Purpose: Laparoscopic gastrectomy in obese patients has been investigated in several studies, but its feasibility has rarely been examined in morbidly obese patients, such as in those with a body mass index (BMI) of ${\geq}30kg/m^2$. The present study aimed to evaluate the technical feasibility and safety of laparoscopic gastrectomy in morbidly obese patients with gastric cancer. Materials and Methods: A total of 1,512 gastric cancer patients who underwent laparoscopic distal gastrectomy (LDG) were divided into three groups: normal (BMI< $25kg/m^2$, n=996), obese (BMI $25{\sim}30kg/m^2$, n=471), and morbidly obese ($BMI{\geq}30kg/m^2$, n=45). Short-term surgical outcomes, including the course of hospitalization and postoperative complications, were compared between the three groups. Results: The morbidly obese group had a significantly longer operating time (240 minutes vs. 204 minutes, P=0.010) than the normal group, but no significant differences were found between the groups with respect to intraoperative blood loss or other complications. In the morbidly obese group, the postoperative morbidity and mortality rates were 13.3% and 0%, respectively, and the mean length of hospital stay was 8.2 days, which were not significantly different from those in the normal group. Subgroup analysis showed that postoperative complication rates were not high in morbidly obese patients, independent of the type of anastomosis technique used and level of lymph node dissection. Conclusions: LDG is technically feasible and safe in morbidly obese patients with a BMI of ${\geq}30kg/m^2$ and early gastric carcinoma. Except for a longer operating time, LDG might represent a reasonable treatment option in these patients.

• Journal of Gastric Cancer
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• v.14 no.3
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• pp.164-172
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• 2014

Purpose: To evaluate the incidence, clinicopathological characteristics, treatment outcomes, prognostic factors, and survival of gastric cancer patients with bone metastases. Materials and Methods: Of 4,617 gastric cancer patients who were treated between 2001 and 2013, 176 patients with bone metastases were analyzed. Results: The incidence of bone metastasis was 3.8%. The most common histopathological subtype was adenocarcinoma (79%) with poor differentiation (60.8%). The median interval from the diagnosis to bone metastasis was 11 months. The median survival time after bone metastasis was 5.4 months. Factors that were associated with longer median survival times included the following: isolated bone metastasis (P=0.004), well-differentiated tumors (P=0.002), palliative chemotherapy (P=0.003), zoledronic acid treatment (P<0.001), no smoking history (P=0.007), and no metastatic gastric cancer at the time of diagnosis (P=0.01). On the other hand, high levels of lactate dehydrogenase (LDH) (hazard ratio [HR]: 1.86; P=0.015), carcinoembryonic antigen (CEA) (HR: 2.04; P=0.002), and carbohydrate antigen (CA) 19-9 (HR: 2.94; P<0.001) were associated with shorter survival times. In multivariate analysis, receiving zoledronic acid (P<0.001) and performance status (P=0.013) were independent prognostic factors. Conclusions: Smoking history, poor performance status, poorly differentiated adenocarcinoma, and high levels of LDH, CEA, and CA 19-9 were shown to be poor prognostic factors, while receiving chemotherapy and zoledronic acid were associated with prolonged survival in gastric cancer patients with bone metastases.

• Journal of Gastric Cancer
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• v.14 no.3
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• pp.156-163
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• 2014

Purpose: Information regarding antimicrobial prophylaxis (AMP) for gastric cancer surgery is limited. The present study investigated the efficacy of single-dose AMP for the prevention of surgical site infection (SSI) in patients undergoing gastrectomy for gastric carcinoma. Materials and Methods: Between 2011 and 2013, 1,330 gastric carcinoma surgery patients were divided into two AMP administration groups depending on the duration of treatment. Postoperative outcomes including morbidity and SSI were compared between the two groups overall and in matched patients. Risk factors for SSI were analyzed. Results: The extended group (n=1,129) received AMP until postoperative day 1 and the single-dose group (n=201) received single-dose AMP only during an operation. Postoperatively, there were no significant differences between the two groups with respect to overall morbidity, mortality, or length of hospital stay. The SSI rate of the single-dose group was not significantly different from that of the extended group overall (4.5% vs. 5.5%, respectively, P=0.556) or in matched patients (4.5% vs. 4.0%, respectively, P=0.801). There was no increase in the SSI rate of the single-dose group compared to the extended group in subgroups based on different clinicopathological and operative factors. Univariate and multivariate analyses revealed male gender, open surgery, and operating time (${\geq}180$ minutes) as independent risk factors for SSI. Conclusions: Single-dose AMP showed no increase in the postoperative SSI rate compared to postoperative extended use in patients undergoing gastrectomy for gastric carcinoma. The efficacy of single-dose AMP requires further investigation in randomized clinical trials specific to gastric cancer surgery.

• Journal of Gastric Cancer
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• v.14 no.4
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• pp.259-265
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• 2014

Purpose: Survival analysis of gastric cancer patients requires knowledge about factors that affect survival time. This paper attempted to analyze the survival of patients with incomplete registered data by using imputation methods. Materials and Methods: Three missing data imputation methods, including regression, expectation maximization algorithm, and multiple imputation (MI) using Monte Carlo Markov Chain methods, were applied to the data of cancer patients referred to the cancer institute at Imam Khomeini Hospital in Tehran in 2003 to 2008. The data included demographic variables, survival times, and censored variable of 471 patients with gastric cancer. After using imputation methods to account for missing covariate data, the data were analyzed using a Cox regression model and the results were compared. Results: The mean patient survival time after diagnosis was $49.1{\pm}4.4$ months. In the complete case analysis, which used information from 100 of the 471 patients, very wide and uninformative confidence intervals were obtained for the chemotherapy and surgery hazard ratios (HRs). However, after imputation, the maximum confidence interval widths for the chemotherapy and surgery HRs were 8.470 and 0.806, respectively. The minimum width corresponded with MI. Furthermore, the minimum Bayesian and Akaike information criteria values correlated with MI (-821.236 and -827.866, respectively). Conclusions: Missing value imputation increased the estimate precision and accuracy. In addition, MI yielded better results when compared with the expectation maximization algorithm and regression simple imputation methods.

• Journal of Gastric Cancer
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• v.14 no.4
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• pp.252-258
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• 2014

Purpose: The macroscopic diagnosis of tumor invasion through the serosa during surgery is not always distinct in patients with gastric cancer. The prognostic impact of the difference between macroscopic findings and pathological diagnosis of serosal invasion is not fully elucidated and needs to be re-evaluated. Materials and Methods: A total of 370 patients with locally advanced pT2 to pT4a gastric cancer who underwent curative surgery were enrolled in this study. Among them, 155 patients with pT3 were divided into three groups according to the intraoperative macroscopic diagnosis of serosal invasion, as follows: serosa exposure (SE)(-) (no invasion, 72 patients), SE(${\pm}$) (ambiguous, 47 patients), and SE(+) (definite invasion, 36 patients), and the clinicopathological features, surgical outcomes, and disease-free survival (DFS) were analyzed. Results: A comparison of the 5-year DFS between pT3_SE(-) and pT2 groups and between pT3_SE(+) and pT4a groups revealed that the differences were not statistically significant. In addition, in a subgroup analysis of pT3 patients, the 5-year DFS was 75.1% in SE(-), 68.5% in SE(${\pm}$), and 39.4% in SE(+) patients (P<0.05). In a multivariate analysis to evaluate risk factors for tumor recurrence, macroscopic diagnosis (hazard ratio [HR], SE(-) : SE(${\pm}$) : SE(+)=1 : 1.01 : 2.45, P=0.019) and lymph node metastasis (HR, N0 : N1 : N2 : N3=1 : 1.45 : 2.20 : 9.82, P<0.001) were independent risk factors for recurrence. Conclusions: Gross inspection of serosal invasion by the surgeon had a strong impact on tumor recurrence in gastric cancer patients. Consequently, the gross appearance of serosal invasion should be considered as a factor for predicting patients' prognosis.

• Journal of Gastric Cancer
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• v.14 no.4
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• pp.246-251
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• 2014

Purpose: There are two surgical procedures for proximal early gastric cancer (EGC): total gastrectomy (TG) and proximal gastrectomy (PG). This study aimed to compare the long-term outcomes of PG with those of TG. Materials and Methods: Between January 2001 and December 2008, 170 patients were diagnosed with proximal EGC at Soonchunhyang University Cheonan Hospital, of which 64 patients underwent PG and 106 underwent TG. Clinicopathologic features, postoperative complications, blood chemistry data, changes in body weight, and oncological outcomes were analyzed and retrospectively compared between both groups. Results: Tumor size was smaller and the number of retrieved lymph nodes was lower in the PG group. The postoperative complication rate was 10.9% in the TG group and 16.9% in the PG group. The incidence of Los Angeles grade C and D reflux esophagitis was significantly higher in the TG group. Hemoglobin level was higher and body weight loss was greater in the TG group at 2, 3, and 5 years postoperatively. The albumin levels at 3 and 5 years were lower in the TG group. There was no significant difference in the 5-year overall survival rates between the two groups (P=0.789). Conclusions: Postoperative complications and oncologic outcomes were observed to be similar between the two groups. The PG group showed better laboratory data and weight loss than did the TG group. Moreover, severe reflux esophagitis occurred less frequently in the PG group than in the TG group. PG can be considered as an effective surgical treatment for proximal EGC.

• Journal of Gastric Cancer
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• v.14 no.4
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• pp.238-245
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• 2014

Purpose: Gastric cancer often occurs in the elderly but is uncommon in young individuals. Whether young patients have different clinical behaviors and outcomes from those of older patients remain unclear. Materials and Methods: We identified 1,366 cases of newly diagnosed noncardia gastric adenocarcinoma from the Kaiser Permanente Northern California Cancer Registry between 2000 and 2010. We then compared the clinicopathological features and survival among the different age groups. Results: The male : female ratio differed significantly between the younger and older patient groups (0.84 in age <50 years vs. 1.52>60 years, P<0.01). More younger patients were Hispanic (54% patients <40 years vs. 19% patients ${\geq}70$ years, P<0.0001), while more older patients were Caucasian (49% patients ${\geq}70$ years vs. 15% patients <40 years; P<0.0001). The diffuse/mixed histological type was more prevalent in younger patients (70% patients <40 years vs. 27% patients ${\geq}70$ years; P<0.0001), whereas the intestinal type was more frequent in older patients (71% in patients ${\geq}70$ years vs. 30% in patients <40 years; P<0.0001). Poorly differentiated adenocarcinoma was more common in the younger patients (80% in patients <40 years vs. 60% in patients ${\geq}70$ years; P=0.016). Survival rates at 1, 2, and 5 years gradually declined with increasing age (overall P=0.0002). Conclusions: Young patients with gastric cancer had more aggressive disease but higher overall survival rates than older patients. Younger Hispanic patients and older Caucasian patients were more likely to be diagnosed with gastric cancer. These differences may be due to biological predisposition and/or environmental exposure.

• Journal of Gastric Cancer
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• v.13 no.3
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• pp.136-148
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• 2013

Purpose: To define the role of robotic gastrectomy for the treatment of gastric cancer, the present systematic review with meta-analysis was performed. Materials and Methods: A comprehensive search up to July 2012 was conducted on PubMed, EMBASE, and the Cochrane Library. All eligible studies comparing robotic gastrectomy versus laparoscopic gastrectomy or open gastrectomy were included. Results: Included in our meta-analysis were seven studies of 1,967 patients that compared robotic (n=404) with open (n=718) or laparoscopic (n=845) gastrectomy. In the complete analysis, a shorter hospital stay was noted with robotic gastrectomy than with open gastrectomy (weighted mean difference: -2.92, 95% confidence interval: -4.94 to -0.89, P=0.005). Additionally, there was a significant reduction in intraoperative blood loss with robotic gastrectomy compared with laparoscopic gastrectomy (weighted mean difference: -35.53, 95% confidence interval: -66.98 to -4.09, P=0.03). These advantages were at the price of a significantly prolonged operative time for both robotic gastrectomy versus laparoscopic gastrectomy (weighted mean difference: 63.70, 95% confidence interval: 44.22 to 83.17, P<0.00001) and robotic gastrectomy versus open gastrectomy (weighted mean difference: 95.83, 95% confidence interval: 54.48 to 137.18, P<0.00001). Analysis of the number of lymph nodes retrieved and overall complication rates revealed that these outcomes did not differ significantly between the groups. Conclusions: Robotic gastrectomy for gastric cancer reduces intraoperative blood loss and the postoperative hospital length of stay compared with laparoscopic gastrectomy and open gastrectomy at a cost of a longer operating time. Robotic gastrectomy also provides an oncologically adequate lymphadenectomy. Additional high-quality prospective studies are recommended to better evaluate both short and long-term outcomes.

• Journal of Gastric Cancer
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• v.13 no.3
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• pp.157-163
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• 2013

Purpose: The aim of this study was to assess clinical correlations with postoperative alteration of p16 DNA methylation, and to clarify whether postoperative changes in the serum DNA methylation status of p16 could be used as a reliable prognostic factor for gastric cancer. Materials and Methods: Fifty-three consecutive gastric adenocarcinoma patients who underwent gastric resection (Chung-Ang University Hospital, Seoul, Korea) were included. DNA methylation of p16 was evaluated by methylation-specific polymerase chain reaction using serum DNA preoperatively and at the 10th postoperative day. The correlation between changes in methylation status and patients' prognosis was analyzed. Results: p16 was methylated in 79.2% of preoperative serum DNA and in 54.7% of postoperative serum DNA, respectively. Methylation in p16 disappeared more frequently in patients who underwent standard D2 lymphadenectomy compared to those who underwent modified D1+ lymphadenectomy (P=0.016). Whereas methylation of preoperative serum DNA was not correlated with survival, patients with postoperative disappearance of p16 methylation showed longer survival than those without postoperative disappearance of p16 methylation in the patients who had gastric cancer with lymph node metastasis (P=0.042). Conclusions: Postoperative disappearance of p16 methylation could be an available prognostic factor for node-positive gastric cancer.

• Journal of Gastric Cancer
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• v.16 no.3
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• pp.152-160
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• 2016

Purpose: Endoscopic diagnosis of gastric cancer (GC) that emerges after eradication of Helicobacter pylori may be affected by unique morphological changes. Using comprehensive endoscopic imaging, which can reveal biological alterations in gastric mucosa after eradication, previous studies demonstrated that Congo red chromoendoscopy (CRE) might clearly show an acid non-secretory area (ANA) with malignant potential, while autofluorescence imaging (AFI) without drug injection or dyeing may achieve early detection or prediction of GC. We aimed to determine whether AFI might be an alternative to CRE for identification of high-risk areas of gastric carcinogenesis after eradication. Materials and Methods: We included 27 sequential patients with metachronous GC detected during endoscopic surveillance for a mean of 82.8 months after curative endoscopic resection for primary GC and eradication. After their H. pylori infection status was evaluated by clinical interviews and $^{13}C$-urea breath tests, the consistency in the extension of corpus atrophy (e.g., open-type or closed-type atrophy) between AFI and CRE was investigated as a primary endpoint. Results: Inconsistencies in atrophic extension between AFI and CRE were observed in 6 of 27 patients, although CRE revealed all GC cases in the ANA. Interobserver and intraobserver agreements in the evaluation of atrophic extension by AFI were significantly less than those for CRE. Conclusions: We demonstrated that AFI findings might be less reliable for the evaluation of gastric mucosa with malignant potential after eradication than CRE findings. Therefore, special attention should be paid when we clinically evaluate AFI findings of background gastric mucosa after eradication (University Hospital Medical Information Network Center registration number: UMIN000020849).